Cooling device having a plurality of controllable cooling elements to provide a predetermined cooling profile

ABSTRACT

A cooling device for removing heat from subcutaneous lipid-rich cells of a subject having skin is provided. The cooling device includes a plurality of cooling elements movable relative to each other to conform to the contour&#39;s of the subject&#39;s skin. The cooling elements have a plurality of controllable thermoelectric coolers. The cooling elements can be controlled to provide a time-varying cooling profile in a predetermined sequence, can be controlled to provide a spatial cooling profile in a selected pattern, or can be adjusted to maintain constant process parameters, or can be controlled to provide a combination thereof.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 11/528,225, now U.S. Pat. No. 9,132,031 Sep. 26, 2006, thedisclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates generally to cooling devices, systems,and methods for removing heat from subcutaneous lipid-rich cells, andmore particularly, but not exclusively, to a cooling device having aplurality of controllable cooling elements to create a spatial coolingprofile and/or a time-varying cooling profile in order to moreefficiently affect subcutaneous lipid-rich cells.

BACKGROUND

Excess body fat increases the likelihood of developing various types ofdiseases such as heart disease, high blood pressure, osteoarthrosis,bronchitis, hypertension, diabetes, deep-vein thrombosis, pulmonaryemboli, varicose veins, gallstones, hernias, and several otherconditions.

In addition to being a serious health risk, excess body fat can alsodetract from personal appearance and athletic performance. For example,excess body fat can form cellulite, which causes an “orange peel” effectat the surface of the skin. Cellulite forms when subcutaneous fatprotrudes into the dermis and creates dimples where the skin is attachedto underlying structural fibrous strands. Cellulite and excessiveamounts of fat are often considered to be unappealing. Thus, in light ofthe serious health risks and aesthetic concerns associated with excessfat, an effective way of controlling excess accumulation of body fat isurgently needed.

Liposuction is a method for selectively removing body fat to sculpt aperson's body. Liposuction is typically performed by plastic surgeonsand dermatologists using specialized surgical equipment thatmechanically removes subcutaneous fat cells via suction. One drawback ofliposuction is that it is a serious surgical procedure, and the recoverymay be painful. Liposuction can have serious and occasionally even fatalcomplications. In addition, the cost for liposuction is usuallysubstantial.

Conventional non-invasive treatments for removing excess body fattypically include topical agents, weight-loss drugs, regular exercise,dieting, or a combination of these treatments. One drawback of thesetreatments is that they may not be effective or even possible undercertain circumstances. For example, when a person is physically injuredor ill, regular exercise may not be an option. Similarly, weight-lossdrugs or topical agents are not an option when they cause an allergic ornegative reaction. Furthermore, fat loss in selective areas of aperson's body cannot be achieved using general or systemic weight-lossmethods.

Other non-invasive treatment methods include applying heat to a zone ofsubcutaneous lipid-rich cells. U.S. Pat. No. 5,948,011 disclosesaltering subcutaneous body fat and/or collagen by heating thesubcutaneous fat layer with radiant energy while cooling the surface ofthe skin. The applied heat denatures fibrous septae made of collagentissue and may destroy fat cells below the skin, and the coolingprotects the epidermis from thermal damage. This method is less invasivethan liposuction, but it still can cause thermal damage to adjacenttissue, and may be painful for the patient.

Another method of reducing subcutaneous fat cells is to cool the targetcells as disclosed in U.S. Patent Publication No. 2003/0220674, theentire disclosure of which is incorporated herein. This publicationdiscloses, among other things, reducing the temperature of lipid-richsubcutaneous fat cells to selectively affect the fat cells withoutdamaging the cells in the epidermis. Although this publication providespromising methods and devices, several improvements for enhancing theimplementation of these methods and devices would be desirable,including providing a plurality of controllable cooling elements tocreate a spatial cooling profile and/or a time-varying cooling profilein order to more efficiently affect subcutaneous lipid-rich cells.

U.S. Patent Publication No. 2003/0220674 also discloses methods forselective removal of lipid-rich cells and avoidance of damage to otherstructures including dermal and epidermal cells. A method for moreefficiently and precisely controlling these effects is desirable.Therefore, a method for spatially cooling lipid-rich cells over apredetermined time-varying cooling profile, selected spatial coolingprofile, or maintaining constant process parameters is also needed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative positions of elements in the drawingsare not necessarily drawn to scale. For example, the shapes of variouselements and angles are not drawn to scale, and some of these elementsare arbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn are not intendedto convey any information regarding the actual shape of the particularelements, and have been solely selected for ease of recognition in thedrawings.

FIG. 1 is an isometric view of a system for removing heat fromsubcutaneous lipid-rich cells in accordance with an embodiment of theinvention.

FIGS. 2A, 2B, 2C, and 2D are isometric views of a cooling device forremoving heat from subcutaneous lipid-rich cells in accordance withembodiments of the invention.

FIG. 3 is an exploded isometric view of the cooling device of FIG. 2Afor removing heat from subcutaneous lipid-rich cells in accordance withan embodiment of the invention.

FIG. 4 is a further exploded isometric view of the cooling device ofFIG. 3 illustrating additional components of the cooling device inaccordance with another embodiment of the invention.

FIG. 5A is an isometric view of a plurality of heat exchangers connectedin series in accordance with another embodiment of the invention. FIG.5B is an isometric top view of a plurality of heat exchangers connectedin series in accordance with yet another embodiment of the invention.FIG. 5C is an isometric bottom view of the heat exchangers in FIG. 5B.

FIG. 6A is an exploded isometric view of one of the heat exchangersshown in FIG. 5A. FIG. 6B is an isometric view of an alternativeconfiguration of a cooling element of a heat exchanger in accordancewith an embodiment of the invention.

FIG. 7 is a cross-sectional view of one of the cooling elements alongline 7-7 of FIG. 5A.

FIG. 8 is an isometric top view of an alternative cooling device forremoving heat from subcutaneous lipid-rich cells in accordance with anembodiment of the invention.

FIG. 9 is an isometric bottom view of the alternative cooling device ofFIG. 8.

FIG. 10 is an exemplary sectional view of a lateral cooling pattern inthe dermis of the skin in accordance with another embodiment of theinvention.

FIG. 11 is a block diagram showing computing system software modules forremoving heat from subcutaneous lipid-rich cells in accordance withanother embodiment of the invention.

DETAILED DESCRIPTION

A. Overview

The present disclosure describes devices, systems, and methods forcooling subcutaneous lipid-rich cells. The term “subcutaneous tissue”means tissue lying underneath the dermis and includes adipocytes (fatcells) and subcutaneous fat. It will be appreciated that several of thedetails set forth below are provided to describe the followingembodiments in a manner sufficient to enable a person skilled in therelevant art to make and use the disclosed embodiments. Several of thedetails and advantages described below, however, may not be necessary topractice certain embodiments of the invention. Additionally, theinvention can include other embodiments that are within the scope of theclaims but are not described in detail with respect to FIGS. 1-11.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present invention. Thus, theoccurrences of the phrases “in one embodiment” or “in an embodiment” invarious places throughout this specification are not necessarily allreferring to the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments.

The headings provided herein are for convenience only and do notinterpret the scope or meaning of the claimed invention.

The present invention is directed toward a cooling device for removingheat from subcutaneous lipid-rich cells of a subject. The cooling deviceincludes a plurality of cooling elements movable relative to each otherso as to be conformable to the skin of the subject.

One aspect is directed toward a cooling device for removing heat fromsubcutaneous lipid-rich cells. The cooling device includes a pluralityof cooling elements contained within interconnected frame membersrotatable about at least one axis, a plurality of heat exchangingelements, and a housing. Alternatively, the cooling device includes aplurality of cooling elements contained on a flexible substrate. Thecooling elements can use a number of cooling technologies including, forexample, thermoelectric coolers, recirculating chilled fluid, vaporcompression elements, or phase change cryogenic devices. One skilled inthe art will recognize that there are a number of other coolingtechnologies that could be used and that the cooling elements need notbe limited to those described here.

Another aspect is directed toward a cooling device having a plurality ofcooling members using thermoelectric Peltier principles or other coolingtechnologies. The cooling device also includes a heat dissipating memberin thermal communication with the cooling members and a plurality ofinterface members having heat exchanging surfaces configured to contacta subject's skin. The cooling members can be capable of reducing atemperature of a region such that lipid-rich cells in the region areaffected while non-lipid-rich cells are not generally affected.

Further aspects include that the cooling device can include a pluralityof interconnected hinged segments for rotating to conform to a bodyportion. Alternatively, the cooling elements may also be disposed on aflexible substrate and movable relative to each other.

Another aspect is directed toward a cooling device having a plurality ofcooling members individually controlled to provide a spatial coolingprofile and/or a time-varying cooling profile. The cooling profile can,for example, be configured to provide cooling members along a perimeterof the cooling device at a lower or a higher temperature than coolingmembers at an interior of the cooling device. Alternatively, the coolingprofile can be configured to provide cooling members in regions of thecooling device at a lower or a higher temperature than cooling membersin adjacent regions of the cooling device. Further aspects include thatthe cooling profile can vary over time to provide a decreasing or anincreasing temperature profile during treatment.

Another aspect is directed toward a method of applying a cooling devicehaving a plurality of cooling elements contained on a plurality ofinterconnected hinged segments, each adjacent pair of hinged coolingelements being rotatable about at least one axis. The cooling elementscan have a plurality of heat exchanging surfaces capable of removingheat from the subject's skin. The method includes rotating hingedsegments containing the cooling elements to achieve a desiredconfiguration of the cooling device, cooling the heat exchangingsurfaces of the plurality of cooling elements to a desired temperature,placing the plurality of cooled heat exchanging surfaces proximate tothe subject's skin, and reducing the temperature of a region such thatlipid-rich cells in the region are affected while non-lipid-rich cellsin the region are not generally affected. Alternatively, the coolingelements may be disposed on a flexible substrate and movable relative toeach other.

Further aspects include a method for applying and maintaining pressureon the contact region. Further aspects include securing the coolingdevice in position with a retention device. Further aspects includeproviding a time-varying profile to increase or decrease the temperatureof the cooling elements over a selected time period. Further aspectsinclude spatially varying the temperature of each cooling element of thecooling device to provide discrete cooling regions in the coolingdevice.

Another aspect is directed toward a system for removing heat fromsubcutaneous lipid-rich cells. The system includes a cooling devicehaving a plurality of frame segments containing cooling elements movablerelative to each other, the frame segments capable of achieving adesired orientation between each other, and a heat sink coupled to thecooling device to dissipate heat generated by the cooling device. In oneembodiment, the frame segments are hinged. When placed proximate to asubject's skin, the plurality of cooling elements can be capable ofreducing a temperature of a region such that lipid-rich cells in theregion are affected while non-lipid-rich cells in the epidermis and/ordermis are not generally affected.

Further aspects include the cooling device being configured to followthe contours of the body. Further aspects include that the coolingdevice includes a handle and/or can include a strap or other retentiondevice for holding the cooling device in a selected position. Furtheraspects include a control system for individually controlling thetemperature of the cooling elements in a predetermined pattern. Furtheraspects include a processing unit for controlling a time-varying coolingprofile of the cooling device.

B. System for Selectively Reducing Lipid-Rich Cells

FIG. 1 is an isometric view of a system 100 for removing heat fromsubcutaneous lipid-rich cells of a subject 101 in accordance with anembodiment of the invention. The system 100 can include a cooling device104 placed at an abdominal area 102 of the subject 101 or anothersuitable area for removing heat from the subcutaneous lipid-rich cellsof the subject 101. Various embodiments of the cooling device 104 aredescribed in more detail below with reference to FIGS. 2-11.

The system 100 can further include a cooling unit 106 and supply andreturn fluid lines 108 a-b connecting the cooling device 104 to thecooling unit 106. The cooling unit 106 can remove heat from a coolant toa heat sink and provide a chilled coolant to the cooling device 104 viathe fluid lines 108 a-b. Examples of the circulating coolant includewater, glycol, synthetic heat transfer fluid, oil, a refrigerant, andany other suitable heat conducting fluid. The fluid lines 108 a-b can behoses or other conduits constructed from polyethylene, polyvinylchloride, polyurethane, and other materials that can accommodate theparticular circulating coolant. The cooling unit 106 can be arefrigeration unit, a cooling tower, a thermoelectric chiller, or anyother device capable of removing heat from a coolant. Alternatively, amunicipal water supply (i.e., tap water) can be used in place of thecooling unit.

As explained in more detail below, the cooling device 104 includes aplurality of thermoelectric cooling elements, such as Peltier-typethermoelectric elements, which can be individually controlled to createa custom spatial cooling profile and/or a time-varying cooling profile.The system 100 can further include a power supply 110 and a processingunit 114 operatively coupled to the cooling device 104. In oneembodiment, the power supply 110 can provide a direct current voltage tothe thermoelectric cooling device 104 to effectuate a heat removal ratefrom the subject 101. The processing unit 114 can monitor processparameters via sensors (not shown) placed proximate to the coolingdevice 104 through power line 116 to adjust the heat removal rate basedon the process parameters. The heat transfer rate can be adjusted tomaintain constant process parameters. Alternately, the processparameters can vary either spatially or temporally. The processing unit114 can be in direct electrical communication through line 112, oralternatively, may be connected via a wireless communication.Alternatively, the processing unit 114 can be preprogrammed to provide aspatially distributed cooling profile and/or a time-varying coolingprofile. The processing unit 114 can include any processor, ProgrammableLogic Controller, Distributed Control System, and the like.

In another aspect, the processing unit 114 can be in electricalcommunication with an input device 118, an output device 120, and/or acontrol panel 122. The input device 118 can include a keyboard, a mouse,a touch screen, a push button, a switch, a potentiometer, and any otherdevice suitable for accepting user input. The output device 120 caninclude a display screen, a printer, a medium reader, an audio device,and any other device suitable for providing user feedback. The controlpanel 122 can include indicator lights, numerical displays, and audiodevices. In alternative embodiments, the control panel 122 can becontained on the cooling device 104. In the embodiment shown in FIG. 1,the processing unit 114, power supply 110, control panel 122, coolingunit 106, input device 118, and output device 120 are carried by a rack124 with wheels 126 for portability. In alternative embodiments, theprocessing unit 114 can be contained on the cooling device 104. Inanother embodiment, the various components can be fixedly installed at atreatment site.

C. Cooling Device Having a Plurality of Cooling Elements

FIGS. 2A, 2B, and 2C are isometric views of a cooling device 104 inaccordance with embodiments of the invention suitable for use in thesystem 100. In this embodiment, the cooling device 104 includes acontrol system housing 202 and cooling element housings 204 a-g. Thecontrol system housing 202 includes a sleeve 308 (FIG. 3) that may slideinto collar 310 and/or may mechanically attach to the cooling elementhousings. The cooling element housings 204 a-g are connected to the heatexchanging elements (not shown) by attachment means 206. The attachmentmeans can be any mechanical attachment device such as a screw or pin asis known in the art. The plurality of cooling element housings 204 a-gcan have many similar features. As such, the features of the firstcooling element housing 204 a are described below with reference symbolsfollowed by an “a,” corresponding features of the second cooling elementhousing 204 b are shown and noted by the same reference symbol followedby a “b,” and so forth. The cooling element housing 204 a can beconstructed from polymeric materials, metals, ceramics, woods, and/orother suitable materials. The example of the cooling element housing 204a shown in FIG. 2A-C is generally rectangular, but it can have any otherdesired shape.

The cooling device 104 is shown in a first relatively flat configurationin FIG. 2A; in a second slightly curved configuration in FIG. 2B; and ina third curved configuration in FIG. 2C. As shown in FIGS. 2B and 2C,each segment of the cooling element housings 204 a-g are rotatablyconnected to adjacent segments and moveable about connection 207 a-f toallow the cooling device 104 to curve. The connection 207 a-f, forexample, can be a pin, a ball joint, a bearing, or other type ofrotatable joints. The connection 207 can accordingly be configured torotatably couple the first cooling element housing 204 a to the secondcooling element housing 204 b. According to aspects of the invention,the first cooling element housing 204 a can rotate relative to thesecond cooling element housing 204 b (indicated by arrow A), eachadjacent moveable pair of cooling elements being such that, for example,the angle between the first and second cooling element housings 204 aand 204 b can be adjusted up to 45°. In this way, the cooling device isarticulated such that it can assume a curved configuration as shown inFIG. 2B or 2C, conformable to the skin of a subject.

One advantage of the plurality of rotatable heat exchanging surfaces isthat the arcuate shape of the cooling device may concentrate the heattransfer in the subcutaneous region. For example, when heat exchangingsurfaces are rotated about a body contour of a subject, the arcuateshape can concentrate heat removal from the skin.

The control system housing 202 can house a processing unit forcontrolling the cooling device 104 and/or fluid lines 108 a-b and/orelectrical power and communication lines. The control system housing 202includes a harness port 210 for electrical and supply fluid lines (notshown for purposes of clarity). The control system housing 202 canfurther be configured to serve as a handle for a user of the coolingdevice 104. Alternatively, the processing unit may be contained at alocation other than on the cooling device.

As shown in FIGS. 2A, 2B, and 2C, the cooling device 104 can furtherinclude at each end of the cooling device 104 retention devices 208 aand 208 b coupled to a frame 304. The retention devices 208 a and 208 bare rotatably connected to the frame by retention device couplingelements 212 a-b. The retention device coupling elements 212 a-b, forexample, can be a pin, a ball joint, a bearing, or other type ofrotatable joints. Alternatively, the retention devices 208 a and 208 bcan be rigidly affixed to the end portions of the cooling elementhousings 204 a and 204 g. Alternately, the retention device can attachto control system housing 202.

The retention devices 208 a and 208 b are each shown as tabs 214, eachhaving a slot 216 therein for receiving a band or elastomeric strap (notshown for purposes of clarity) to retain the cooling device 104 in placeon a subject 101 during treatment. Alternatively, the cooling device maynot contain any attached retention device and may be held in place byhand, may be held in place by gravity, or may be held in place with aband, elastomeric strap, or non-elastic fabric (e.g., nylon webbing)wrapped around the cooling device 104 and the subject 101.

As shown in FIGS. 2A-2C, the cooling element housings 204 a-g have afirst edge 218 and an adjacent second edge 220 of a reciprocal shape toallow the cooling device 104 to mate and, thus, configure in a flatconfiguration. The first edge 218 and the second edge 220 are generallyangular in the Figures; however, the shape could be curved, straight, ora combination of angles, curves, and straight edges that provide areciprocal shape between adjacent segments of the cooling elementhousings 204 a-g.

FIG. 2D shows an isometric view of an alternative cooling device 104 inaccordance with embodiments of the invention suitable for use in thesystem 100. In this embodiment, the cooling device 104 includes aplurality of heat exchanging elements 300 a-g contained within aflexible substrate 350. As described with respect to FIGS. 2A-2C,adjacent heat exchanging elements 300 a-g are fluidicly coupled inseries by fluid lines 328.

According to aspects of the embodiment, the cooling elements 302 a-g maybe affixed to the flexible substrate 350, or may be embedded in theflexible substrate 350. The flexible substrate 350 can be constructedfrom polymeric materials, elastomeric materials, and/or other suitablematerials. The flexible substrate 350 can further be an elastomer suchas silicone or urethane or can be a fabric, such as nylon. The flexiblesubstrate 350 can also be a thin polymer such as polypropylene or ABS.The example of the flexible substrate 350 shown in FIG. 2D is generallyrectangular, but can have any other desired shape, including a matrixconfiguration or an anatomy specific shape. According to aspects of thisembodiment, the flexible substrate 350 acts as a living hinge betweencooling elements 302 a-g to allow the cooling elements 302 a-g toconform to the skin of a subject.

FIG. 3 is an exploded isometric view of a cooling device 104 inaccordance with one embodiment of the invention suitable for use in thesystem 100. In this embodiment, the cooling device 104 includes a frame304 having a plurality of rotatably connected segments 305 a-g. Therotatably connected segments 305 a-g are connected by hinges 306 a-g.Alternatively, the rotatably connected segments 305 a-g of the frame 304could be connected by a connection that allows rotation, such as a pin,living hinge, flexible substrate, such as webbing or fabric, or thelike. According to one aspect of the invention, the links or hinges aremade of plastic to insulate the cooling elements from each other.

A plurality of heat exchanging elements 300 a-g are contained on theframe 304. The heat exchanging elements 300 a-g include cooling elements302 a-g having covers 301 a-g. The covers 301 a-g are affixed on a topside of the cooling elements 302 a-g. The covers 301 a-g may be affixedby various mechanical means as described further herein and as are knownin the art. According to aspects of the invention, the covers 301 a-gare fluidicly sealed to the cooling elements 302 a-g. According tofurther aspects of the invention, the hinges 306 a-g are configured soas to be adjacent to the subject's skin, in use, to maintain closeproximity between the heat exchanging elements 300 a-g when the heatexchanging elements 300 a-g are in a rotated position.

The cooling elements 302 a-g are attached by cooling element attachmentmeans 307 to the frame 304 such that the first heat exchanging element300 a is located at the first segment 305 a of the frame 304 and thesecond heat exchanging element 300 b is located at the second segment305 b of the frame 304. The cooling element attachment means 307 areshown as a tab 313 extending from the frame 304 and a screw 315 fixedlyattaching the tab 313 of the frame 304 to the cooling elements 302 a-g.Alternatively, mechanical fixation devices as are known in the art maybe used.

The cooling elements 302 a-g of the cooling device 104 are generallyconfigured to rotate to allow the cooling device 104 to conform to anarcuate portion of a subject 101. Once positioned on a subject 101, thecooling device 104 can further be strapped to or otherwise configured tobe releasably attached to the subject 101. The cooling elements 302 a-gcan be configured to move relative to each other or rotate to positionthe cooling elements 302 a-g for applying pressure to the treatment areaduring operation. Cooling elements 302 a-g are movable or rotatablerelative to each other such that cooling device 104 is conformable tothe skin of the subject. These features are described in more detailbelow with reference to specific examples of the cooling devices.

The first cooling element 302 a can include the cooling element housing204 a, a fluid inlet port 310 and a fluid outlet port 316 a. The fluidinlet port 310 is fluidicly coupled to the supply fluid line 108 a. Asshown in FIG. 3, adjacent cooling elements are fluidicly coupled inseries by fluid lines 328 at fluid inlet ports 314 a-f and fluid outletports 316 a-f. The cooling element 302 g further includes a fluid outletport 312 fluidicly coupled to the return fluid line 108 b.

One expected advantage of providing cooling elements fluidicly coupledin series is a uniform flow rate through each cooling element 302 a-g toprovide more consistent cooling of the cooling device. Another expectedadvantage of providing cooling elements 302 a-g fluidicly coupled inseries is fewer supply lines into the cooling device to provide a morereliable, less cumbersome and easier to house fluid flow configurationfor the cooling device.

FIG. 4 is a further exploded isometric view of the cooling device ofFIG. 3 in accordance with one example of the invention for use in thesystem 100. This further exploded view is substantially similar topreviously described examples, and common acts and structures areidentified by the same reference numbers. Only significant differencesin operation and structure are described below. The cooling device 104includes cooling elements 302 a-g having a plurality of thermoelectriccoolers 402 configured to reduce the temperature of a subcutaneousregion of the subject 101 for selectively affecting lipid-rich cells inthe region. The plurality of thermoelectric coolers 402, also known as aPeltier-type element, has a first side 404 and a second side 406. Thefirst side 404 is in thermal communication with the cooling element 302,and the second side 406 is in thermal communication with an interfacemember 418. The thermoelectric coolers 402 can be connected to anexternal power supply (not shown) to transfer heat between the firstside 404 and the second side 406. One suitable thermoelectric cooler isa Peltier-type cooling element (model # CP-2895) produced by TETechnologies, Inc. in Traverse City, Mich.

The thermoelectric coolers 402 are contained within the segments 305 a-gof the frame 304. According to aspects of the invention, the frame 304may contain individual guides for each thermoelectric cooler 402.Alternatively, the thermoelectric coolers 402 may be retained on thecooling elements 302 a-g, for example, by thermal epoxy or by acombination of solder, mechanical compression and thermal grease.

As shown in FIG. 4, the plurality of cooling elements 302 a-g canfurther include a plurality of interface members 418 in thermalcommunication with the thermoelectric cooler 402 having heat exchangingsurfaces 420 for transferring heat to/from the subject 101. In oneexample, the interface members 418 are generally planar, but in otherexamples, the interface members 418 are non-planar (e.g., curved,faceted, etc.) The interface members 418 can be constructed from anysuitable material with a thermal conductivity greater than 0.05Watts/Meter Kelvin, and in many examples, the thermal conductivity ismore than 0.1 Watts/Meter Kelvin. Examples of suitable materials includealuminum, other metals, metal alloys, graphite, ceramics, some polymericmaterials, composites, or fluids contained in a flexible membrane.

By applying power to the thermoelectric coolers 402, heat can beeffectively removed from the subject's skin to a circulating fluid incooling elements 302 a-g. For example, applying a current to thethermoelectric coolers 402 can achieve a temperature generally below 37°C. on the first side 404 of the thermoelectric coolers 402 to removeheat from the subject 101 via the interface members 418. Thethermoelectric coolers 402 pull heat from the second side 406 to thefirst side 404 where the heat is then transferred to the circulatingfluid. The cooling unit 106 then removes the heat from the circulatingfluid.

The thermoelectric coolers 402 can be configured to withdraw asufficient amount of heat quickly from the subject 101 without using ahigh-current power supply for the cooling unit 106. In order tofacilitate thermal transfer, the interface members 418 can be analuminum plate configured generally the same dimensions at thethermoelectric coolers 402. According to aspects of the invention, thethermoelectric coolers 402 can be Peltier-type thermoelectric elementsrated at about 160 watts. As such, the cooling device 104 can cool aportion of the subject's skin from a temperature of about 37° C. toabout −20° C. quickly and effectively. The cooling unit 106 can use anormal voltage power supply (e.g., 120 VAC) because the powerconsumption is not excessive. This enables the system to be used inhospitals, clinics, and small offices without more costly high voltageelectrical systems.

FIG. 5A is an isometric view of a plurality of heat exchanging elements300 a-g connected in series with the housing removed to better show theplurality of heat exchanging elements 300 a-g and interconnected fluidlines. According to aspects of the invention, the heat exchangingelements 300 a-g are rotatably contained on linked segments of the frame304 to provide a cooling device that is wider than it is tall. Thus, thecooling device is compliant and will form to follow contours. Accordingto aspects of the invention, the cooling device is dimensionally smallin a first dimension so that curvature of the treatment area in a seconddimension does not significantly impact the amount of surface area incontact between the skin and the cooling device.

According to further embodiments of the invention, FIG. 5B is anisometric top view of a plurality of heat exchangers connected in seriesby a hinge 350 a, 350 b, wherein the hinge connection is connecteddirectly to the heat exchanger 302 a, 302 b. The hinge 350 a, 350 b asshown in FIG. 5B is a piano hinge that extends along adjacent edges ofthe heat exchanger 300 a, 300 b for the length of the heat exchanger 300a, 300 b, alternatively, the hinge 350 a, 350 b may extend a portion ofthe length of the adjacent sides of the heat exchanger 300 a, 300 b orthe hinged connection may include a plurality of hinges 350 a 350 b.Unlike in FIG. 5A, no frame is employed to connect the heat exchangers300 a, 300 b or provide support for the hinged connection between heatexchangers 300 a, 300 b. FIG. 5C is an isometric bottom view of the heatexchangers in FIG. 5B. According to further aspects of the invention,alternative hinged mechanical connections as is known in the art may beused alone or in combination; or, alternative chemical connections suchas flexible adhesives or a living hinge as is known in the art may beused in the hinged connections; or, electromechanical connections suchas magnets may be used between heat exchangers to connect the heatexchangers.

FIG. 6A is an exploded isometric side elevation view of the heatexchanging element 300 a shown in FIG. 5A to further show the flow offluid in the heat exchanging element 300 a. Like reference symbols referto like features and components in the Figures. As shown in FIG. 6A, theheat exchanging element 300 a can include a fluid chamber 610 having aserpentine shape within the cooling element 302 a. As shown in FIG. 6B,the heat exchanging element 300 a can include fins 612 to direct fluidflow through the fluid chamber 610. The fluid chamber 610 can be influid communication with the associated fluid ports such that fluid cancirculate through the fluid chamber 610. The fluid chamber 610 can beconfigured to accept fluid coolants, such as water, glycol, a syntheticheat transfer fluid, oil, refrigerants, air, carbon dioxide, nitrogen,and argon. According to further aspects of the invention, the fluidchamber 610 may be configured in a variety of configurations as is knownin the art in order to distribute the fluid throughout the coolingelement 302 a.

FIG. 7 is a cross-sectional view of one cooling element 302 a. Thecooling element 302 a is fluidicly sealed by cover 301 a containing ano-ring seal 722, held in place by an attachment means 326. According toaspects of the invention, the cooling element 302 a can further includeat least one sensing element 710 proximate to the heat exchangingsurface 420 (FIG. 4). The sensing element 710, for example, can begenerally flush with the heat exchanging surface 420. Alternatively, itmay be recessed or protrude from the surface. The sensing element 710can include a temperature sensor, a pressure sensor, a transmissivitysensor, a bio-resistance sensor, an ultrasound sensor, an opticalsensor, an infrared sensor, a heat flux sensor, or any other desiredsensor as described further herein.

In one example, the sensing element 710 can be a temperature sensorconfigured to measure the temperature of the first heat exchangingsurface 420 and/or the temperature of the skin of the subject 101. Forexample, the temperature sensor can be configured as a probe or as aneedle that penetrates the skin during measurement. Examples of suitabletemperature sensors include thermocouples, resistance temperaturedevices, thermistors (e.g., neutron-transmutation-doped germaniumthermistors), and infrared radiation temperature sensors. In anotherexample, the sensing element 710 can be an ultrasound sensor configuredto measure crystallization or change in viscosity of subcutaneous fat inthe treatment region of a subject. In yet another example, the sensingelement 710 can be an optical or infrared sensor configured to monitoran image of the treatment region to detect, for example, epidermalphysiological reactions to the treatment. The sensing element 710 can bein electrical communication with the processing unit 114 via, forexample, a direct wired connection, a networked connection and/or awireless connection.

Accordingly, the cooling device 104 can be in electrical communicationwith the processing unit 114, and the cooling temperature can beautomatically adjusted by the processing unit 114. According to furtheraspects of the invention, the temperature of the interface member 418can be sensed by the sensing element 710 and the sensed electricalsignal can be converted by the processing unit 114 into a process valuefor the temperature. In one embodiment, the processing unit 114 caninclude a Proportional, Integral and Derivative controller, which canadjust the power output to the thermoelectric coolers 402 to achieveand/or maintain the desired temperature.

According to further aspects of the invention, the sensing element 710can alternatively be a pressure sensor to sense the pressure exerted bythe cooling element 302 a against the subject 101. In one embodiment,the interface member 418 can be attached to the frame 304 such thatpressure applied against the heat exchanging element 300 a istransferred via the housing 204 a to the pressure sensor. The pressuresensor can alternatively be configured to sense the pressure in thefluid chamber 610 for monitoring pressure variations in the fluidchamber 610. Alternatively, the pressure could be inferred from forceand the known contact area of the cooling elements. For example, thesensing element 710 can be any type of load-sensitive pressure sensingelement such as a load cell (model # LC201-25) produced by OMEGAEngineering, Inc. in Stamford, Conn. Direct pressure measurement couldalso be performed by placing a pressure measurement membrane directly atthe interface between the cooling element and the skin.

The cooling elements 302 a-g can have many additional embodiments withdifferent and/or additional features without detracting from theoperation of the elements. For example, an adjacent cooling element mayor may not have a sensing element proximate to the heat exchangingsurface. Alternatively, the cooling elements can be constructed from amaterial that is different from that of the adjacent cooling element.

FIG. 8 shows an isometric view of a plurality of thermoelectric coolerscontained in a matrix design. FIGS. 8 and 9 are isometric views of analternative cooling device for removing heat from subcutaneouslipid-rich cells in accordance with an embodiment of the invention. Asshown in FIGS. 8 and 9, the cooling device 810 includes a coolingelement 804 configured in a planar matrix. The cooling device 810 caninclude a band 812 for retaining the cooling element 804 in place duringuse. The cooling device can further include a handle 814, a wiringharness 818 and a flap 816 for releasably securing the band 812 to thecooling element 804. The cooling element 804 can further include asleeve 822 as described further above.

As shown in FIG. 9, the cooling element 804 includes a planar matrix 824including a plurality of thermoelectric coolers 826. The thermoelectriccoolers 826 are contained on a flexible substrate 830. The flexiblesubstrate 830 can be an elastomer such as silicone or urethane or can bea fabric, such as nylon. According to further aspects, the flexiblesubstrate 830 can be a thin polymer such as polypropylene or ABS. Asdescribed in greater detail herein, the thermoelectric coolers 826 canhave small protective interface plates (not shown) glued to the coldsurface of the thermoelectric coolers 826 with a thermal epoxy.According to alternative embodiments of the invention, additionalmechanical restraints can further be included in the flexible substrate830 to capture the thermoelectric coolers 826. As described in greaterdetail herein, the thermoelectric coolers 826 can include a heatexchanger (shown and described with respect to FIGS. 3-7) on the hotside to cool the hot side. According to aspects of this embodiment, eachthermoelectric cooler 826 can have a corresponding heat exchanger toprovide increased flexibility to the planar matrix. Alternately, asingle flexible heat exchanger can be coupled to the hot side of thethermoelectric coolers (e.g., a bladder or other flexible membrane thatwater can be circulated through).

According to alternative aspects of the embodiment, the planar matrix824 can further include temperature or other sensors (not shown)captured between the interface plate and the thermoelectric coolersand/or can have a separate sleeve that houses temperature sensors asfurther discussed herein.

D. Operation of the Cooling Device

FIG. 10 is an exemplary sectional view of a lateral cooling pattern inthe dermis of the skin. The cooling pattern radiates from the coolingelements 302 a-f through the epidermis and dermis of the skin such thatwhen it affects the targeted dermis layer containing the lipid-richcells, the cooling pattern forms a uniform cooling layer and any gapsbetween the segments of the frame are mitigated. One expected advantageof this cooling pattern is that the cooling of the dermis layer isuniform during treatment. FIG. 10 discloses cooling device 104 appliedto a generally flat portion of a subject's body. Cooling elements 302a-f of the cooling device are movable relative to each other (as shownin FIGS. 2B, C and D), to conform to the contours of the subject's skin.

Without being bound by theory, it is believed that, in operation,effective cooling from the cooling device 104, which cools throughconduction, depends on a number of factors. Two exemplary factors thatimpact heat removal from the skin area are the surface area of thecooling element and the temperature of the interface member. Whenconduction is between two materials that are placed in physical contact,i.e., the skin and the cooling element, there is a certain amount ofthermal resistance known as contact resistance. The contact resistancetakes the form of a temperature differential between the two materials.Higher contact resistance means less effective cooling; therefore, inthe cooling device it is desirable to minimize contact resistance.

One means to minimize contact resistance and maximize the contactsurface area is with an interface member that is flexible and willconform to the natural body contours. According to alternative aspects,contact pressure can be reduced by increasing the pressure of theapplicator on the skin. Surface pressure has an additional benefit in askin cooling application. Sufficient pressure on the skin can causeinternal capillaries to constrict, temporarily reducing the flow ofblood into the treatment region. Reduced blood flow into the treatmentarea allows the area being cooled to cool more efficiently and improvesthe effectiveness of the treatment.

Thus, according to aspects of the invention, the cooling device alsoincorporates a flexible strapping material or belt that wraps around thesubject following the curvature of the cooling device. By tightening thestrapping, pressure is applied and can be maintained between the subjectand the cooling device. According to aspects of the invention, the strapcan incorporate a hoop or d-ring through which the strapping can belooped to provide mechanical advantage in tightening the strap.According to further aspects of the invention, the strap alsoincorporates Velcro or a latch or buckle to hold the pressure once thestrap has been tightened.

In operation, an operator can hold the cooling device 104 in one hand bygrasping the control system housing 202 or another type of suitablehandle (not shown). Then the cooling elements 302 a-g can be moved orrotated to achieve a desired orientation. The operator can place thecooling device 104 having the cooling elements 302 a-g in the desiredorientation proximate to the subject's skin to remove heat from asubcutaneous region of the subject 101. In one embodiment, the operatortightens retention devices 208 a-b affixed to the cooling device 104 toapply pressure to the subject's skin. In another embodiment, theoperator can manually press the cooling device 104 against the subject'sskin. The operator can also monitor and control the treatment process bycollecting measurements, such as skin temperatures, from the sensingelement 710. By cooling the subcutaneous tissues to a temperature lowerthan 37° C., more preferably lower than 25° C., subcutaneous lipid-richcells can be selectively affected. The affected cells are then resorbedinto the patient through natural processes.

According to aspects of the invention, interface members 418, forexample thin aluminum plates, are mounted to the bottom of thethermoelectric coolers in a manner to ensure good thermal contactbetween the thermoelectric coolers and the interface members. Theinterface members can be coupled to the cooling element by a variety ofmechanical fixation means such as are known in the art. For example, thecoupling means can include using thermally conductive epoxy or usingthermal grease such as zinc oxide.

In operation, cooling is efficiently distributed through the heatexchanging elements 300 a-g. For example, the cooling device includes aseries of interface members 418 approximately 1 mm in thickness. Theinterface members 418 are in thermal communication with the coolingelements 302 a-g by mechanical fixation such as thermal epoxy. Thecooling elements 302 a-g are cooled by a plurality of thermoelectriccoolers to provide a more efficient cooling system to the treatmentregion. The cooling elements 302 a-g are contained on segments that aremovable relative to each other to conform to the contours of thesubject's skin. Alternatively, the cooling elements are rotatablerelative to each other, similar to the joined segments of a metal watchband, thus allowing the assembly to curve.

As designed, the interface members and cooling elements protect thethermoelectric coolers while maintaining good heat transfer between thethermoelectric coolers and the skin. The interface members are sizedsuch that they do not present a significant thermal mass. In one design,each thermoelectric cooler could be 1″×1.5″. The interface member oraluminum plate could also be 1″×1.5″ with a thickness of 0.04″. If thethermoelectric coolers' cooling power is approximately 10 W, which isappropriate based on the heat flux expected to conduct from the skin,then the aluminum plate would cool from an ambient temperature of 20° C.to a treatment temperature of −10° C. in about 7 seconds. The change ininternal energy of the plate is described by the following equation:ΔE=ρ·V·C·ΔTwhere ΔE is the change in internal energy, ρ is the material density, Vis the material volume, C.° is the heat capacity of the material, and ΔTis the temperature change. In the problem described above, the volume ofthe aluminum plate is V=1 in×1.5 in×0.04 in or 0.06 in³ (9.8×10−7 m3).For a typical grade of aluminum, C.°=875 J/kg*° C. and ρ=2770 kg/m3.Solving the equation using these constants:ΔE=2770 kg/m3*9.8×10−7 m3*875 J/kg*° C.*30° C.=71.3 J

If the thermoelectric coolers have a cooling power of 10 W, then 71.3 Jcould be removed from the aluminum plate in 7.1 seconds, as is shown inthe calculation below:71.3 J/(10 J/second)=7.13 seconds

A small gap or recess in the frame at the skin surface may be includedin one embodiment. Prior to applying the cooling device to the skin, athermally conducting fluid or coupling agent can be applied to thedevice and to the skin to minimize contact resistance and increase heattransfer between the cooling device and the skin. This coupling agentwill fill the gap in the cooling device and allow for limited lateralconduction between the thermoelectric coolers' plates. This will createa more uniform temperature gradient across the surface area of the skinwhen the cooling is applied to the skin.

The coupling agent may be applied to the skin or to the interface memberto provide improved thermal conductivity. The coupling agent may includepolypropylene glycol, polyethylene glycol, propylene glycol, and/orglycol. Glycols, glycerols, and other deicing chemicals are efficientfreezing-point depressants and act as a solute to lower the freezingpoint of the coupling agent. Propylene glycol (CH3CHOHCH2OH) is oneexemplary component of deicer or non-freezing coupling agents. Othercomponents include polypropylene glycol (PPG), polyethylene glycol(PEG), polyglycols, glycols, ethylene glycol, dimethyl sulfoxide,polyvinyl pyridine, calcium magnesium acetate, sodium acetate, and/orsodium formate. The coupling agent preferably has a freezing point inthe range of −40° C. to 0° C., more preferably below −10° C. as furtherdescribed in U.S. Provisional Application 60/795,799, entitled CouplingAgent For Use With a Cooling Device For Improved Removal of Heat FromSubcutaneous Lipid-Rich Cells, filed on Apr. 28, 2006, hereinincorporated in its entirety by reference.

One expected advantage of using the cooling device 104 is thatsubcutaneous lipid-rich cells can be reduced generally withoutcollateral damage to non-lipid-rich cells in the same region. Ingeneral, lipid-rich cells can be affected at low temperatures that donot affect non-lipid-rich cells. As a result, lipid-rich cells, such assubcutaneous adipose tissue, can be affected while other cells in thesame region are generally not damaged even though the non-lipid-richcells at the surface are subject to even lower temperatures. Anotherexpected advantage of the cooling device 104 is that it is relativelycompact because the cooling device 104 can be configured as a handhelddevice. Yet another advantage is that the cooling device can be appliedto various regions of the subject's body because the cooling elements302 a-g can be adjusted to conform to any body contour. Another expectedadvantage is that by pressing the cooling device 104 against thesubject's skin, blood flow through the treatment region can be reducedto achieve efficient cooling. Yet another expected advantage is the useof pressure by constriction of the band to restrict blood flow to thetreatment region and thereby reduce heat transfer (by mass transport).Thus, the band can not only provide a means for holding the coolingelement in place, but also ensures good thermal contact between thecooling device and the skin, and further constricts the flow of blood inthe treatment region. Still another expected advantage is that theplurality of the cooling elements 302 a-g more efficiently remove heatfrom the skin compared to a single cooling element.

E. Spatially Controlled Cooling Element Profile

Many skin cooling devices rely on a relatively thick piece of aluminumor other conductive material between a thermoelectric cooler or othercooling source and the skin. When a cooling device is applied to arelatively insulating material, such as skin tissue, the aluminum platebecomes isothermal and maintains a constant temperature profile acrossthe skin's surface. The drawback of this design is that when the deviceinitially cools, or during thermal cycling, the thermal mass presentedby the aluminum plate requires a large cooling power. This eithertranslates into increased cooling time or increased power required fromthe cooling device or both.

According to aspects of the invention, the cooling device has a lowthermal mass that will still maintain a constant temperature profileacross the skin's surface. Further, according to aspects of theinvention, a plurality of cooling elements are provided to allowdifferent regions of the skin to be treated at different temperaturesduring one treatment session. There are some circumstances where it maybe desirable to cool different regions of the skin to differenttemperatures or for different time periods. According to aspects of theinvention, each thermoelectric cooler can be individually controlled tocool different regions of the skin to different temperatures and/or fordifferent time periods and/or to ensure uniform temperature throughoutthe treatment region. One reason this may be desirable is that thecomposition of tissue is different in different locations of the body.Some regions have thicker layers of adipose tissue than others, whichinfluence the thermal response of the skin. In other regions, thepresence of bone or other organs will affect the heat transfer to theskin.

According to aspects of the invention, a spatially controlledtemperature profile can provide more efficient cooling to the treatmentregion. The plurality of thermoelectric coolers allows the coolingdevice to accommodate spatial cooling. For example, thermoelectriccoolers contained at the perimeter of the cooling device may have alower or higher temperature or duration than thermoelectric coolerscontained at the interior of the cooling device because of differentboundary conditions in the different areas of the treatment zone.According to aspects of the invention, the cooling device will quicklyand efficiently cool skin to a prescribed temperature. In addition, thecooling device described here has the additional ability to treat alarge area in a single treatment while cooling different regions todifferent temperatures and/or for different durations.

This variation in localized cooling could alternatively be achievedusing a cooling device that is relatively small such that manytreatments are performed, cooling to different temperatures in differentregions. However, this type of cooling device would require manytreatments, thereby increasing the overall treatment time and theopportunity for operator error. In addition, a cooling device with alarge thermal mass would require a longer cooling time during eachtreatment.

According to aspects of the invention, the device can accommodatespatially controlled cooling temperature profiles which may provide atleast the following advantages: (1) increased efficiency; (2) decreasedpower consumption with comparable efficacy; (3) increased patientcomfort; or (4) decreased treatment time. For example, according toaspects of the invention, the plurality of thermoelectric coolers willallow adjustment for anatomical differences between patients byselectively enabling or disabling portions of the apparatus based onanatomical differences of the patient. One example includes disablingthe thermoelectric coolers around bony anatomy for patient comfort orfor power conservation.

Alternatively, a particular pattern of controlled cooling may becustomized to match an individual patient's pattern of cellulite, thusincreasing the efficacy of the treatment. Similarly, treatment regionsrequiring a higher intensity of treatment may be pre-identified byultrasound or other devices. The device can then be spatially controlledto provide higher intensity treatment to pre-identified areas. Furtheradvantages include increased patient comfort and safety by allowingspatial control of cooling to accommodate unnatural anatomy (e.g. lumps,blemishes, nipples, hairy areas, scars, wounds, presence of implants,jewelry, or areas of heightened sensitivity.)

A further advantage of spatial control of the device includes utilizingonly a subset of the cooling elements in order to treat only the regionrequiring treatment. It is advantageous to use one device that canaccommodate small and large treatment regions without over treating(e.g. a large device that cannot be spatially controlled) or having tomove the device multiple times thus extending the treatment time (e.g. atreatment device smaller than the treatment region). Thus, according toaspects of the invention, a selected region of thermoelectric coolerscan be controlled to a few degrees warmer than another region ofthermoelectric coolers. Alternatively, a first region of the coolingdevice can be turned off while a second region of the cooling device isactivated, such that only a selected region of the subject is treated,thus limiting the treatment region. Other advantageous spatiallycontrolled patterns include treating areas within the treatment regionmore intensely, conserving power by alternating thermoelectric coolers,increasing cooling at a perimeter in order to provide a uniform coolingpattern across the treatment area, and a combination of these spatiallycontrolled patterns in order to increase treatment efficacy, reducetreatment time, decrease power consumption and provide for patientcomfort and safety.

F. Time-Varying Cooling Profiles

In certain embodiments, once a desired temperature is achieved, thetemperature of the region can be maintained for a predetermined periodof time. The cooling cycle can be terminated by separating the heatexchanging surfaces 420 a-g from the skin. After a certain period oftime, if desired, the cooling device 104 can be reapplied to the sameportion of the skin as described above until the lipid-rich cells areaffected an amount sufficient to produce a desired reduction inlipid-rich cells. In another embodiment, the cooling device 104 can beapplied to a different portion of the skin as described above toselectively affect lipid-rich cells in a different subcutaneous targetregion.

Alternatively, the cooling elements 302 a-g can be controlled accordingto a predetermined time-varying cooling profile to cool, heat, re-cool,and/or cool in a stepped temperature pattern over time. In particular,according to aspects of the invention, patterns of controlled coolingover time provide at least the following advantages: (1) increasedefficiency; (2) decreased power consumption with comparable efficacy;(3) increased patient comfort; or (4) decreased treatment time. Oneexemplary cooling pattern includes cooling to −5° for 15 minutes,warming to 30° for 5 minutes, cooling to −3° for 10 minutes. Accordingto aspects of the present invention, any desired time-varying coolingprofile can be programmed into the device. For example, a gradual orstepped cooling rate may decrease power requirements. Alternatively, arapid cooling rate may be used in order to supercool the treatmentregion. Exemplary cooling rates include 5 to 1000 degrees per minute,more preferably 30 to 120 degrees per minute, and most preferably 35 to100 degrees per minute.

One expected advantage of controlling the time-temperature profile ofthe device is that in practice, tissue is sensitive to cooling rates andthus tissue damage can be controlled by controlling the rate of coolingof the treatment region. Further, cooling the treatment region down overan extended period of time, or in phases, will increase patient comfort.

Another expected advantage of several of the embodiments described aboveis that the cooling device 104 can selectively reduce subcutaneouslipid-rich cells without unacceptably affecting the dermis, epidermis,and/or other tissues. Another expected advantage is that the coolingdevice 104 can simultaneously selectively reduce subcutaneous lipid-richcells while providing beneficial effects to the dermis and/or epidermis.These effects may include: fibroplasia, neocollagenesis, collagencontraction, collagen compaction, collagen density increase, collagenremodeling, and acanthosis (epidermal thickening). In the treatment ofcellulite, it is expected that dermal thickening above the herniatingsuperficial fat lobules will help reduce the appearance of cellulite andimprove the longevity of the effect. Another expected advantage is thatthe cooling device 104 can conform to various body contours of a subjectby rotating or moving the cooling elements 302 a-g to achieve a desiredorientation. Yet another expected advantage is that the cooling device104 can be configured as a handheld device for ease of operation.Furthermore, another expected advantage is that the system 100 with thehandheld cooling device 104 and the rack-mounted processing unit 114 andcooling unit 106 are compact and efficient such that the methoddescribed above can be administered in an outpatient clinic or adoctor's office instead of in a hospital. Yet another expected advantageis that the cooling device 104 can be strapped in place to free theclinician's hands and allow the clinician to do other tasks with thetreatment is in process.

G. Method of Applying Cooling Devices with a Plurality of Rotatable orMovable Cooling Elements

In operation, the angle between the heat exchanging surfaces 420 isselected by rotating or moving the cooling elements 302 a-g. The anglebetween the cooling elements 320 a-g is often selected to conform theheat exchanging surfaces 320 a-g to various body contours of the subject101 and/or a desired clamping arrangement. In the embodiment shown inFIG. 2A, the angle between the heat exchanging surfaces 320 a-g can begenerally 180°, i.e., the heat exchanging surfaces 320 a-g are generallycoplanar for applying the cooling device to a treatment region. In theembodiment shown in FIG. 2B, the angle can be less than 180° to allowthe cooling device to curve about a subject's body. In the embodimentshown in FIG. 2C, the cooling device is further curved to conform to asubject's body. In other embodiments, the angle can be any angle toconform to a subject's body, as would be recognized by one skilled inthe art.

After configuring the cooling elements 302 a-g, an operator places thecooling device 104 proximate to the skin of the subject 101. In theembodiment shown in FIG. 2A (where the angle is in a generally flatconfiguration), the cooling elements 302 a-g are initially placed flatagainst a subject's skin. The operator then rotates or moves the coolingdevice to conform to a subject's body. The cooling device can betightened by a strap, and a pressure can be increased by tightening thestrap further. Optionally, the pressure sensor can be used to sense theclamping pressure applied via the interface members 418, and the sensedclamping force can be processed by the processing unit 114 and displayedon the output device 120. The pressure can then be adjusted based on thedisplayed values. Depending on the location of the cooling device, thepressure, for example, can be higher than the systolic pressure in theskin to impede or block the blood flow into the treatment region.Applying such pressure enables more effective cooling of the targetregion because there is less blood flow to transfer core body heat tothe treatment region.

Applying the cooling device with pressure to the subject's skin orpressing against the skin can be advantageous to achieve efficientcooling. In general, the subject 101 has a body temperature of about 37°C., and the blood circulation is one mechanism for maintaining aconstant body temperature. As a result, blood flow through the dermisand subcutaneous layer of the region is a heat source that counteractsthe cooling of the subdermal fat. As such, if the blood flow is notreduced, cooling the subcutaneous tissues would require not onlyremoving the specific heat of the tissues but also that of the bloodcirculating through the tissues. Thus, reducing or eliminating bloodflow through the treatment region can improve the efficiency of coolingand avoid excessive heat loss from the dermis and epidermis.

By cooling the subcutaneous tissues to a temperature lower than 37° C.,subcutaneous lipid-rich cells can be selectively affected. In general,the epidermis and dermis of the subject 101 have lower amounts ofunsaturated fatty acids compared to the underlying lipid-rich cellsforming the subcutaneous tissues. Because non-lipid-rich cells usuallycan withstand colder temperatures better than lipid-rich cells, thesubcutaneous lipid-rich cells can be selectively affected whilemaintaining the non-lipid-rich cells in the dermis and epidermis. Anexemplary range for the cooling elements 302 a-g can be from about −20°C. to about 20° C., preferably from about −20° C. to about 10° C., morepreferably from about −15° C. to about 5° C., more preferably from about−10° C. to about 0° C.

The lipid-rich cells can be affected by disrupting, shrinking,disabling, destroying, removing, killing, or otherwise being altered.Without being bound by theory, selectively affecting lipid-rich cells isbelieved to result from localized crystallization of highly saturatedfatty acids at temperatures that do not induce crystallization innon-lipid-rich cells. The crystals can rupture the bi-layer membrane oflipid-rich cells to selectively necrose these cells. Thus, damage ofnon-lipid-rich cells, such as dermal cells, can be avoided attemperatures that induce crystal formation in lipid-rich cells. Coolingis also believed to induce lipolysis (e.g., fat metabolism) oflipid-rich cells to further enhance the reduction in subcutaneouslipid-rich cells. Lipolysis may be enhanced by local cold exposure,inducing stimulation of the sympathetic nervous system.

H. Computing System Software Modules

FIG. 11 is a functional diagram showing exemplary software modules 940suitable for use in the processing unit 114. Each component can be acomputer program, procedure, or process written as source code in aconventional programming language, such as the C++ programming language,and can be presented for execution by the CPU of processor 942. Thevarious implementations of the source code and object and byte codes canbe stored on a computer-readable storage medium or embodied on atransmission medium in a carrier wave. The modules of processor 942 caninclude an input module 944, a database module 946, a process module948, an output module 950, and, optionally, a display module 951. Inanother embodiment, the software modules 940 can be presented forexecution by the CPU of a network server in a distributed computingscheme.

In operation, the input module 944 accepts an operator input, such asprocess setpoint and control selections, and communicates the acceptedinformation or selections to other components for further processing.The database module 946 organizes records, including operatingparameters 954, operator activities 956, and alarms 958, and facilitatesstoring and retrieving of these records to and from a database 952. Anytype of database organization can be utilized, including a flat filesystem, hierarchical database, relational database, or distributeddatabase, such as provided by a database vendor such as OracleCorporation, Redwood Shores, Calif.

The process module 948 generates control variables based on sensorreadings 960, and the output module 950 generates output signals 962based on the control variables. For example, the output module 950 canconvert the generated control variables from the process module 948 into4-20 mA output signals 962 suitable for a direct current voltagemodulator. The processor 942 optionally can include the display module951 for displaying, printing, or downloading the sensor readings 960 andoutput signals 962 via devices such as the output device 120. A suitabledisplay module 951 can be a video driver that enables the processor 942to display the sensor readings 960 on the output device 120.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number, respectively. When the claims usethe word “or” in reference to a list of two or more items, that wordcovers all of the following interpretations of the word: any of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

The above detailed descriptions of embodiments of the invention are notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whilesteps are presented in a given order, alternative embodiments mayperform steps in a different order. The various embodiments describedherein can be combined to provide further embodiments.

In general, the terms used in the following claims should not beconstrued to limit the invention to the specific embodiments disclosedin the specification, unless the above detailed description explicitlydefines such terms. While certain aspects of the invention are presentedbelow in certain claim forms, the inventors contemplate the variousaspects of the invention in any number of claim forms. Accordingly, theinventors reserve the right to add additional claims after filing theapplication to pursue such additional claim forms for other aspects ofthe invention.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theinvention can be modified, if necessary, to employ cooling devices witha plurality of cooling elements, thermally conductive devices withvarious configurations, and concepts of the various patents,applications, and publications to provide yet further embodiments of theinvention.

These and other changes can be made to the invention in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the invention to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all cooling that operates in accordancewith the claims. Accordingly, the invention is not limited by thedisclosure, but instead its scope is to be determined entirely by thefollowing claims.

We claim:
 1. A system for removing heat from subcutaneous lipid-richcells of a subject, the system comprising: a plurality of spaced apartcooling elements, wherein the individual cooling elements are configuredto contain a liquid coolant and include a heat exchanging surface and asensing element; a flexible substrate including a first surface and asecond surface, the flexible substrate carrying the cooling elementssuch that the cooling elements are movable relative to one another andthe heat exchanging surfaces and the first surface of the substrate facea subject when the heat exchanging surfaces remove heat fromsubcutaneous tissue of the subject to affect subcutaneous lipid-richcells of the subject; a cooling unit in fluid communication with thecooling elements, the cooling unit is configured to remove heat from theliquid coolant that has absorbed heat from the subcutaneous lipid-richcells; and a processing unit in communication with the sensing elementand programmed to individually control the cooling elements such thatthe cooling elements cool the subcutaneous lipid-rich cells of thesubject to a sufficiently low temperature for at least 10 minutes so asto selectively disrupt the subcutaneous lipid-rich cells.
 2. The systemof claim 1, wherein the flexible substrate comprises a polymericmaterial, elastomeric material, or both, and wherein at least one of theheat exchanging surfaces has a thermal conductivity greater than about0.05 Watts/Meter Kelvin.
 3. The system of claim 2, wherein the sensingelement is proximate to one of the heat exchanging surfaces andcomprises a temperature sensor, a heat flux sensor, and/or a pressuresensor.
 4. The system of claim 1, wherein the sensing element includes atemperature sensing element positioned to detect a temperature of thesubject's skin and/or a temperature of a portion of one of the coolingelements facing the subject.
 5. The system of claim 1, wherein thesensing element is proximate to one of the heat exchanging surfaces,wherein the processing unit includes a processor in electricalcommunication to the sensing element and configured to convertelectrical signals from the sensing element into an operating parameter;and the system further comprising: a database electrically connected tothe processor to store the operating parameter.
 6. The system of claim1, wherein the flexible substrate provides living hinges to allow thecooling elements to rotate relative to one another.
 7. The system ofclaim 1, wherein the heat exchanging surfaces are close enough to oneanother such that the heat exchanging surfaces cooled by the coolingelements remove heat from the subcutaneous tissue to form asubstantially uniform cooling layer generally below all of the heatexchanging surfaces to disrupt the subcutaneous lipid-rich cells.
 8. Asystem for removing heat from subcutaneous lipid-rich cells of asubject, the system comprising: a plurality of cooling elements, theindividual cooling elements configured to contain a liquid coolant andincluding heat exchanging surfaces; a flexible substrate including afirst surface and a second surface, wherein the flexible substratecarries the cooling elements such that the flexible substrate provides aliving hinge between adjacent cooling elements; a processing unitconfigured to individually control each of the cooling elements andbeing programmed to control the cooling elements such that the heatexchanging surfaces cooled by the cooling elements remove heat fromsubcutaneous tissue of the subject to form a substantial uniform coolinglayer generally below the heat exchanging surfaces to disrupt thesubcutaneous lipid-rich cells of the subject.
 9. The system of claim 8,further comprising: a cooling unit configured to remove heat from theliquid coolant that has passed through the cooling elements; and atleast one fluid line fluidically coupling the cooling unit to thecooling elements to deliver the liquid coolant to the cooling elements.10. The system of claim 9, wherein the cooling unit includes a heat sinkthat absorbs heat from the liquid coolant.
 11. The system of claim 8,wherein each of the cooling elements includes a fluid chamber in thermalcommunication with one of the heat exchanging surfaces such that theliquid coolant flows through the fluid chambers to remove heat from thesubcutaneous tissue.
 12. The system of claim 11, wherein the fluidchambers are serpentine shaped.
 13. The system of claim 11, wherein thecooling elements are fluidically connected in series.
 14. The system ofclaim 8, wherein the cooling elements are embedded in the flexiblesubstrate and positioned between the first surface and the secondsurface.
 15. The system of claim 8, wherein the cooling elements areaffixed to the substrate.
 16. The system of claim 8, wherein the coolingelements are configured to reduce a temperature of the subcutaneoustissue such that the subcutaneous lipid-rich cells are affected whilenon-lipid-rich cells proximate to the heat exchanging surfaces are notsignificantly affected.
 17. The system of claim 8, further comprising atleast one fluid line fluidically connecting the cooling elements. 18.The system of claim 8, further comprising a sensing element proximate toone of the heat exchanging surfaces.
 19. The system of claim 18, whereinthe sensing element comprises a temperature sensor, a heat flux sensor,and/or a pressure sensor.
 20. The system of claim 18, wherein thesensing element includes a temperature sensing element positioned todetect a temperature of the subject's skin and/or a temperature of aninterface member of the cooling element.
 21. The system of claim 8,wherein the cooling elements each include a sensing element, wherein thesystem further comprises: a processor in electrical communication to thesensing elements and configured to convert electrical signals from thesensing elements into an operating parameter; and a databaseelectrically connected to the processor to store the operatingparameter.
 22. The system of claim 21, wherein the processor includes acontrol module for controlling a temperature of the subcutaneous tissuebased on the operating parameter, wherein a temperature of thesubcutaneous tissue is controlled based on a selected spatialtemperature profile.
 23. A system for removing heat from subcutaneouslipid-rich cells of a subject, the system comprising: a plurality ofcooling elements movable relative to one another, wherein each coolingelement includes a thermally conductive plate with a heat exchangingsurface and a back surface, a thermoelectric cooler positioned to coolthe back surface, a fluid chamber configured to hold liquid coolant inthermal communication with the thermoelectric cooler while thethermoelectric cooler cools the back surface, and a sensing element; acooling unit in fluid communication with the cooling elements, whereinthe cooling unit is configured to remove heat from liquid coolant thathas absorbed heat from the thermoelectric coolers; and a processing unitin communication with the sensing elements and programmed toindividually control each cooling element based on output from one ormore of the sensing elements such that the heat-exchanging surfaces coolthe subcutaneous lipid-rich cells to a sufficiently low temperature forselectively disrupting the subcutaneous lipid-rich cells.
 24. The systemof claim 23, wherein the heat exchanging surfaces are close enough toone another such that the heat exchanging surfaces cooled by the coolingelements remove heat from the subject's subcutaneous tissue to form asubstantially uniform cooling layer extending below all of the heatexchanging surfaces to disrupt the subcutaneous lipid-rich cells. 25.The system of claim 23, wherein substantially all of the back surfacesare covered by the thermoelectric coolers.